The present invention is directed in general to monitoring operational parameters and fault-related information of a vehicle, and more specifically, to a method and apparatus for recovering from the loss of communications between an on-board monitoring apparatus on the vehicle and a remote site, such as a remote monitoring and diagnostics center.
Cost efficient operation of vehicle fleets requires minimization of vehicle down time, and especially the avoidance of vehicle failures while in service. Failure of a major vehicle system can cause serious damage, require costly repairs, and introduce significant operational delays into the fleet. An in-service failure is an especially costly event as it requires dispatching a replacement vehicle. Further, if the vehicle is a railroad locomotive, a track segment may be rendered unusable until the disabled train is moved. The health of the vehicle and its constituent sub-assemblies is therefore of significant concern to the fleet operator.
One apparatus for minimizing vehicle down time measures performance and fault-related operational parameters of the vehicle during operation. This information can provide timely and important indications of potential failures and valuable diagnostics information for actual faults. With timely and nearly continuous access to vehicle performance data, it is possible for repair experts to predict and/or prevent untimely failures.
One such apparatus, a vehicle on-board monitor, collects and aggregates vehicle operational performance and fault related data and transmits it to a remote site, including a remote monitoring and diagnostics center. The vehicular data is collected periodically by the on-board monitor, or in response to predetermined triggering events that occur within the vehicle during operation. Usually, anomalous or fault data is brought to the attention of the vehicle operator, but the vehicle itself lacks the necessary hardware and software elements to diagnose the fault or offer repair recommendations. It is therefore advantageous to utilize the on-board monitor to collect and aggregate the information and at the appropriate time send it to the remote monitoring and diagnostics service center, where data analysis tools operate on the data to identify the root cause of potential or actual faults. Vehicle operation and maintenance experts also analyze the received data to develop repair recommendations for preventative maintenance or to correct faults. Historical patterns of anomalous data can be important clues to an accurate diagnosis and repair recommendation. Finally, the lessons learned from failure modes in a single vehicle can also be applied to similar fleet vehicles so that the necessary preventive maintenance can be performed before a line-of-service breakdown occurs. If the data analysis process identifies incipient problems, certain performance aspects of the vehicle can be derated to avoid further system degradation and limit violations of operational thresholds until the vehicle can undergo repair at a repair facility.
An on-board monitor aboard a vehicle monitors and collects data indicative of the vehicle operation from several vehicular control systems. This data is stored within the on-board monitor and downloaded to a remote monitoring and diagnostics center for analysis and the generation of repair recommendations. Typically, the downloads occur on a periodic basis, but certain fault events or anomalous conditions on the vehicle will trigger an immediate download, referred to as a call-home event.
A temporary loss of communications between the on-board monitor and the receiving site, typically a remote monitoring and diagnostics center, can occur when the geographical location of the vehicle does not permit a communications path to be established between the vehicle and the remote site (i.e., the communications link is lost or disrupted) or when the vehicle is undergoing repair. Also, installation of new communications hardware on the vehicle requires the execution of a communications system commissioning process, prior to which the vehicle may be unable to connect to the remote site. Therefore the vehicle cannot download the periodic data files nor contact the remote monitoring and diagnostics center if a xe2x80x9ccall-homexe2x80x9d event occurs.
In order to overcome these disadvantages, the present invention sets forth a sequence of events during which the on-board monitor will try to communicate with the remote site. The on-board monitor utilizes call timers and call logs for determining when to initiate calls back to the remote site based on whether previous calls (as logged in the call logs) were successful or unsuccessful.